1. Field of Invention
The present invention relates to a digital television system including a transmission means for transmitting audiovisual information in a digital datastream on a plurality of channels.
2. Description of Related Art
Digital television systems are becoming increasing established, notably in the field of pay TV systems. Encrypted or scrambled audiovisual information is sent, usually by a satellite or, satellite/cable link, to a number of subscribers, each possessing a decoder or receiver/decoder capable of descrambling the transmitted program for subsequent viewing. Terrestrial digital broadcast systems are also known. Recent systems have also used the broadcast link to transmit other data, in addition to or as well as audiovisual data, such as computer programs or interactive applications to the decoder or to a connected PC.
One of the advantages of digital television lies in the number of channels that are available in such systems and the flexibility that is available to the television service provider regarding what channel choices or menus may be made available to a subscriber of the service. Other than a standard set of subscription channels, the system may also include, for example, a pay-per-view function enabling a subscriber to pay for a particular film, sporting event etc.
With the increasing channel availability, one service that is proving increasingly popular is the simultaneous transmission of the same sporting event as viewed from a number of different camera angles. In a similar manner, for a tennis or football competition, a number of matches in the same cup may be broadcast simultaneously the same evening on different channels. In combination with a pay-per-view type service, the subscriber may choose to pay for one of the matches broadcast on one channel, all of the matches that evening, all the matches in the tournament over the next few weeks etc.
Whilst the viewer benefits from the increased choice available, the large numbers of channels that are available may prove distracting and, in practice, a viewer may often have difficulty managing the viewing possibilities available.
Some stations provide, for example, a menu or home channel where the viewer can look at what is currently playing on all the channels, each channel being displayed in a small section in a grill displayed on the television screen. Where a large number of channels are displayed, however, it can be difficult for a viewer to adequately discern what is happening on any one channel. For these reasons, this solution is not particularly suitable for simultaneous live broadcasts on more than a few channels.